JPH0634234B2 - Pattern recognizer - Google Patents

Description

The present invention relates to a pattern recognition device, and more particularly to a pattern recognition device using a pattern matching method.

[Conventional technology]

In pattern recognition devices such as character recognition and voice recognition, a pattern matching method is generally used in which a standard pattern prepared in advance is compared with an input unknown input pattern.

The recognition determination in the pattern matching method is performed by obtaining a standard pattern having a minimum matching distance value obtained by performing a matching process between a standard pattern and an unknown input pattern and using the standard pattern as a recognition result.

It is necessary to avoid erroneously recognizing the entered character or voice as one of the standard patterns when it does not exist in the standard pattern. There is a method of determining that the standard pattern is not the standard pattern and excluding it when the standard pattern becomes larger than the reject value.

On the other hand, when the value of the matching distance of the standard pattern to be obtained is larger than the value of the matching distance with any erroneous standard pattern, a character or voice different from the correct character or voice may be recognized.

In this case, if a relatively small reject value is set for a standard pattern that is easily misrecognized, the unknown input pattern will not be recognized unless it is very similar to that standard pattern, and the value of the matching distance with the incorrect standard pattern will be the minimum. However, if it does not fall below the relatively small reject value, it will not be erroneously recognized.

In this way, by setting an appropriate reject value according to the situation of misrecognition for each standard pattern, misrecognition can be reduced.

In a conventional pattern recognition device, these reject values are set empirically as a human sense, by performing a recognition test so that the user can judge the test results.

[Problems to be solved by the invention]

The above-described conventional pattern recognition device has a problem in that the reject value must be set to an ambiguous value depending on human senses.

An object of the present invention is to provide a pattern recognition device that can automatically change to an appropriate reject value depending on whether or not a recognition result is correct.

[Means for solving problems]

The pattern recognition device of the present invention includes (A) a standard pattern memory that stores N standard patterns prepared in advance, and (B) a reject that is a predetermined threshold value set for each of the N standard patterns. A reject value memory for storing a value, (C) performing a matching process between the input unknown input pattern and the N standard patterns, and the value of the obtained matching distance exceeds the reject value of each of the standard patterns. A matching processing unit that recognizes that the specific standard pattern that is the smallest among those that does not exist matches the unknown input pattern and outputs information of the specific standard pattern, (D) in the matching processing unit A determination result input section for inputting determination result information as to whether or not the output information of the specific standard pattern is correct, (E) the determination result Based on the information, an update value K relating to the specific reject value R read from the reject value memory corresponding to the specific standard pattern, K = R-s (s is a constant value sufficiently smaller than R) Alternatively, it is calculated to be a value slightly smaller than R by a predetermined formula such as K = R × t (t is a constant value slightly smaller than 1), and the updated value K is written in the read position of the reject value memory. The determination result control unit is provided.

〔Example〕

 Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of the pattern recognition apparatus of the present invention.

In FIG. 1, the standard pattern memory 1 stores N standard patterns prepared in advance.

On the other hand, the reject value memory 2 stores a reject value that is a predetermined threshold value set for each of the N standard patterns.

When a certain unknown input pattern is input, the matching processing unit 3 reads N standard patterns in the standard pattern memory 1 one after another and reads N reject values in the reject value memory 2 one after another.

Then, the unknown input pattern and each of the standard patterns are subjected to matching processing, and the matching distance value obtained in the result does not exceed each reject value of the standard pattern. The standard pattern of is recognized as matching the unknown input pattern, and the information of the standard pattern is output.

Based on this output information, the user determines whether or not the recognition result is correct, and only when the recognition result is incorrect, the user inputs the number of the incorrect standard pattern from the determination result input unit 4 as the determination result information. To do.

The determination result control unit 5 reads the reject value of the number from the reject value memory 2, calculates the update value of the read reject value by a method of subtracting “4” which is a predetermined value, and rejects it. It is written in the original position of the value memory 2.

FIG. 2 (a) is an information structure diagram showing information in the reject value memory of the first and second embodiments.

Further, FIG. 2 (b) is an information structure diagram showing information of the standard pattern memories of the first and second embodiments.

N standard patterns P1, P2, ... Shown in FIG.
...... Rejection values corresponding to PN are shown as N reject values R1, R2, ... R in FIG. 2 (a).
Each is shown in N.

The operation of the first embodiment of the present invention will be described below.

For example, first, R1, R2, ... RN in FIG.
, All store "50", while the second
It is assumed that the voice pattern in which P1 is "1", P2 is "ni", and P3 is "san" in FIG.

An unknown input pattern is input to the matching processing unit 3, and the matching processing unit 3 performs matching processing with all the standard patterns. As a result, the matching distance value of P2 is the minimum and the matching distance value is R2. 50 "
It is assumed that the value is smaller.

As a result, the matching processing unit 3 recognizes the unknown input pattern as "ni" and outputs the information.

However, when the determination result information indicating that the recognition result is erroneous recognition is input from the determination result input unit 4 by the user, the determination result control unit 5 reads “50” of R2, and then reads “4”. R2 of the reject value memory 2 is updated to "46" by using "46" obtained by subtracting "" as the update value.

Therefore, thereafter, the matching processing unit 3 does not recognize the unknown input pattern as "ni" unless the value of the matching distance of P2 becomes smaller than "46".

Similarly, if the user inputs determination result information indicating another erroneous recognition, the reject value of the standard pattern is “4”.
Only subtracted and updated.

If the user inputs the determination result information indicating the same standard pattern P2 erroneous recognition, the reject value R2 of P2 is input.
Is further subtracted by "4" and updated to "42", which makes it more difficult to be erroneously recognized.

In this way, in this embodiment, since the reject value is updated in accordance with the erroneous recognition situation for each standard pattern, the erroneous recognition can be reduced.

Next, the operation of the second embodiment of the present invention will be described.

FIG. 3 is a block diagram showing a second embodiment of the pattern recognition apparatus of the present invention.

The determination result control unit 5a in which FIG. 3 differs from FIG. 1 calculates the update value of the reject value read from the reject value memory 2 by a method of multiplying by a predetermined value “0.9”. , It is written in the original position of the reject value memory 2.

For example, as in the case of the first embodiment, all of “50” are assigned to R1, R2, ... RN in FIG. 2 (a).
On the other hand, it is assumed that P1 in FIG. 2B stores a voice pattern “1”, P2 stores “ni”, and P3 stores “san”.

An unknown input pattern is input to the matching processing unit 3, and the matching processing unit 3 performs matching processing with all the standard patterns. As a result, the matching distance value of P2 is the minimum and the matching distance value is R2. 50 "
It is assumed that the value is smaller.

As a result, the matching processing unit 3 recognizes the unknown input pattern as "ni" and outputs the information.

However, when the determination result information indicating that the recognition result is an erroneous recognition is input from the determination result input unit 4 by the user, the determination result control unit 5 reads “50” of R2, and reads “0”. R2 of the reject value memory 2 is updated to this value with "45" multiplied by .9 "as the update value.

Therefore, thereafter, the matching processing unit 3 will not recognize the unknown input pattern as "ni" unless the value of the matching distance of P2 becomes smaller than "45".

Similarly, if the user inputs determination result information indicating another erroneous recognition, the reject value of the standard pattern is set to "0.
9 "is multiplied and updated.

If the user inputs the determination result information indicating the same standard pattern P2 erroneous recognition, the reject value R2 of P2 is input.
Is further multiplied by “0.9”, and the fractional part is truncated and updated to “40”, which makes it more difficult to be erroneously recognized.

In this way, in this embodiment, since the reject value is updated in accordance with the erroneous recognition situation for each standard pattern, the erroneous recognition can be reduced.

〔The invention's effect〕

As described above, the pattern recognition device of the present invention has an effect that it is possible to reduce erroneous recognition by being able to automatically change to an appropriate reject value depending on whether or not the recognition result is correct. ing.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a pattern recognition apparatus of the present invention, and FIG. 2 (a) is an information structure diagram showing information of a reject value memory of the first and second embodiments. FIG. 3B is an information structure diagram showing the information of the standard pattern memories of the first and second embodiments, and FIG. 3 is a block diagram showing the second embodiment of the pattern recognition apparatus of the present invention. 1 ... Standard pattern memory, 2 ... Reject value memory, 3 ... Matching processing unit, 4 ... Judgment result input unit,
5, 5a ... Judgment result control unit.

Claims (1)

[Claims] 1. A standard pattern memory for storing N standard patterns prepared in advance, and a reject value which is a predetermined threshold value set for each of the N standard patterns. (C) Matching processing between the input unknown input pattern and the N standard patterns, and the obtained matching distance value does not exceed the respective reject values of the standard patterns. A matching processing unit that recognizes that the specific standard pattern that is the smallest is the same as the unknown input pattern and outputs the information of the specific standard pattern; (D) The specific output that is output by the matching processing unit. A determination result input section for inputting determination result information as to whether or not the standard pattern information is correct; (E) based on the determination result information, The update value K relating to the specific reject value R read from the reject value memory corresponding to the specific standard pattern is K = R−s (s is a constant value sufficiently smaller than R) or K = R × A determination result control unit that calculates a value slightly smaller than R by a predetermined expression such as t (t is a constant value slightly smaller than 1) and writes the updated value K at the read position of the reject value memory, A pattern recognition device comprising: